[PATCH]: arm64: factor work_pending state machine to C

[Will Deacon]

On Fri, Jul 29, 2016 at 02:16:07PM -0400, Chris Metcalf wrote:
> On 7/11/2016 8:19 AM, Mark Rutland wrote:
> >On Mon, Jul 11, 2016 at 12:42:37PM +0100, Will Deacon wrote:
> >>On Fri, Jul 08, 2016 at 04:49:01PM +0100, Will Deacon wrote:
> >>>On Fri, Jul 08, 2016 at 11:43:50AM -0400, Chris Metcalf wrote:
> >>>>I am hopeful that this patch [1] can be picked up for the 4.8 merge window
> >>>>in the arm64 tree.  As I mentioned in my last patch series that included
> >>>>this patch [2], I'm hopeful that this version addresses the performance
> >>>>issues that were seen with Mark's original patch.  This version tests the
> >>>>TIF flags prior to calling out to the loop in C code.
> >>>I still need to get round to measuring that again. This might also
> >>>conflict with a late fix I just sent for 4.7.
> >>FWIW, I've failed to measure any performance overhead from this change,
> >>so it certainly looks better thsn Mark's original patch from that angle.
> >FWIW, likewise, with perf bench sched atop of v4.7-rc6.
> 
> I don't see this commit pushed up as part of what's in 4.8 so far. Any chance
> it's going to go in later in the merge window?  I'm just hoping to trim down the
> task-isolation series by being able to drop this patch from its next iteration... :-)

I'll queue it up for 4.9, once I've had a closer look.

Will